To what extent can political leanings and party affiliation be attributed to biology, organism and nature than to culture, environment and nurture? An intriguing comparison of voting habits between identical and non-identical twins, details of which can be found here, suggests that our leanings and affiliation have more to do with the former than we might otherwise grant. Still, the question remains what conclusions, definitive, provisional or otherwise, can be drawn from this study.
Ordinary views on political leanings and party affiliation hold that, within certain limits, rational, self-interested individuals are most likely to identify with those parties whose stated views best correspond to the individuals’ own needs and values. Individuals make choices at the ballot box between rival positions, and these choices follow from needs and values as shaped by a lifetime of experience within particular environments. Therefore, on this ordinary view, individuals’ party affiliation follows from experience within certain environments.
Yet the study in question casts doubts on just such views by examining how twins, as individuals having gained experience within the same formative environment, compare with regards to party affiliation. The study briefly recalls the importance of this consideration by stating:
Twins provide a unique natural experiment for research. Identical twins share 100% of their genes, while non-identical twins – like non-twin siblings – share about 50%. Both identical and non-identical twins normally share the same environment while growing up. By comparing the differences and similarities between them we can identify how much of a quirk, disease, or trait is due to a genetic predisposition or environmental and cultural factors. Because twin studies adjust for culture and upbringing they are an ideal way to study political allegiances.
In sum, twins provide a privileged look at the factors behind party affiliation in that their situation acts as a control on environmental relativity, all the while isolating genetic elements that might also play a role therein.
The results were striking, particularly with regards to individuals farther right on the political spectrum:
We found that voting Conservative (or not) is strongly influenced by genetics. When it came to voting Tory, we found that 57% of the variability (differences or similarity) between people’s voting preferences were due to genetic effects. This percentage is called heritability. That means the identical twins were more likely to vote the same way than the non-identical twins – suggesting an underlying genetic influence was stronger than environmental or random factors.
In the Tory case, more than half of the variability owes to factors stemming from underlying genetic make-up. More simply, identical twins showed much greater convergence and predictability than did non-identical twins. Having controlled for environment, the study, naturally, attributes this to greater similarities in genetic make-up between identical twins than between non-identical twins. Had environment been the determining factor in party affiliation, we would have expected to find no difference in affiliation predictability between identical and non-identical twins: the results would have been the same for either group.
Certainly, the study takes care to qualify its findings when it notes both that similarities in genetic make-up play a greater role at the conservative end of the spectrum and also that environmental factors can override genetic factors of the kind seen above. To that end, consider the following cases:
The exception seemed to be voting for the Liberal Democrats, which was affected entirely by environment, with no genetic influence. Identical twins showed exactly the same level of disparity in preference for the Lib Dems as non-identical twins. Geography also played a possible role – as voting for the SNP in Scotland was also completely environmental.
In short, genetic factors cannot account for all cases across the board, and it is important to remember the limits to the conclusions that we might draw. For genetics does not always prove reliable predictive indicators for political leanings and party affiliation.
A further consideration gives us reason to hesitate over what conclusions should be drawn therefrom. Notably, if political leanings and party affiliation are predominantly determined in certain cases by underlying genetic factors, we may ask what room this leaves for political consensus, convergence and fruitful discussion in the public sphere. For, if our affiliations are determined purely by biology and organism, individuals, due to their different genetic make-ups, are unlikely to come to any meaningful consensus if already opposed on an issue. The fact that biological make-up cannot be accounted for in self-reflexive accounts as environment can strengthens this worry all the further. In the end, our positions appear far less reasoned in discourse than they might otherwise, and we are left to wonder just how much such studies might undermine with regards to political praxis.